AP Biology

Answer: B, A gene that can control the activation or repression of other genes is called a regulatory gene.

Key Takeaway: Regulatory genes control the expression of other genes. These genes can code for or protein or RNA as in the case of microRNAs. Regulatory genes can code for activator or repressor proteins. Both types of proteins bind to operators or promoters on genes to activate or repress transcription. An example of a regulatory gene is the CAP gene, which is involved in the positive control of the lac operon in prokaryotes.